Window cords are coupled to vertical drop window coverings to provide for adjustments in the vertical portions of the windows shielded by such coverings. The cords often extend downwardly to a position slightly above floor height or to a position at floor height, although they may sometimes be disposed as high as several feet above floor height. Such adjustments are typically made by manipulating cords, chains, strings or equivalent flexible tension elements. In a typical window horizontal venetian blind, for instance, the position of the blind over a window and the orientation of light control blades are set by pulling or relaxing cords coupled to the blinds through pulleys in the frame headrail of the blind unit. Such adjustments generally require pulling or relaxing simultaneously an array of a plurality of cords, the cords most often being arrayed in pairs but also in triple and quadruple arrays. For convenience in making such adjustments such cords have traditionally been coupled by a pull tassel in a continuous loop suspended from the headrail.
One problem existing with such conventional venetian blind assemblies is that one lift cord may be moved relative to adjacent lift cord so that the slats of the blind will be raised or lowered in an unequal or skewed manner. This results in an unattractive appearance of the blind assembly. Accordingly, lift cords of conventional blind assemblies have been knotted together in an attempt to assure that the cords will move evenly together to obtain even lifting or lowering of the slats. The knot, however, presents an unattractive appearance and, unless securely knotted, may allow slippage of one cord with respect to the adjacent cord. Alternatively, a cord equalizer also has been provided, in addition to a pull tassel, in order to securely lock adjacent cords together to prevent relative slippage between the cords as to assure even raising or lowering of the slats of a blind assembly. Preferably these cord equalizer devices are designed to be unobtrusive and present a small structure which will not distract from the cord configurations.
However, such tassels and equalizers for pull cords for window coverings, such as drapes, blinds or the like, potentially can be dangerous for small children. If the cords are so connected together to form a continuous loop, the cords can act as a noose for a small child if the child's head or other body part gets caught between them. This problem is particularly acute if adults fail to properly secure the cords on the window or door frame and allow them to dangle near the floor, or an infant crib.
These window cords present an attractive but hazardous invitation to infants to play with such cords. The infants are fascinated by the cords, particularly since the cords move when touched. However, many parents do not appreciate the dangers presented by the dangling cords, or when they do, may tie, clip or cleat the cords to shorten the cords. Nevertheless, even aware parents are sometimes negligent in adjusting the height of the cord after they have adjusted the position of the window covering.
As a result of these problems resulting from dangling cords many children die annually from strangulation by playing with such cords. In addition, a considerable number of children probably become injured every year by playing with such cords but such injuries are not reported.
Nevertheless, the available statistical information indicates that an average of one child per month is strangled needlessly by pull cord window coverings, and 86% of these deaths occurred in horizontal venetian blinds (ref: Journal American Medical Association Jun. 4, 1997-vol 277, No. 21). In response to this tragic statistic many of the manufacturers of blinds have in recent years redesigned the pull cord system to reduce the rate of fatalities. The equalizer has been removed altogether. The pull cord loop has been cut and a tassel has been placed on each string, or some type of breakaway safety tassel has been provided. These methods helped to increase child safety but reduced the quality of the blind by making it harder to equalize. Presently, the standard is to cut the cord and put tassels at the end of each cord and place the excess cord slack out of reach of the child whenever the blind is used. If the cords were placed out of reach of children at all times this could possibly solve most of the cord strangulations. However, such solutions leave much to be desired, and none of these solutions address the issue of cord slack pulled between the blinds when the blind is completely lowered. Of course, for user convenience, the need for an equalizer, albeit dangerous, also still remains.
As indicated above, the window coverings industry is generally moving away from such looped cords due to the hazards they present, particularly for small children who may inadvertently become entangled in the pull-tassel-coupled cord loop. As a result, a number of alternatives are being explored for releasably attaching the cord ends together, thereby permitting simultaneous manipulation of the cords, while allowing the cords to be separated when a force is exerted between them. One prior art solution to this pull-tassel cord coupling problem is found in U.S. Pat. No. 4,909,298 (incorporated herein by reference) in which two pull cords are coupled to a tassel device that has two discrete and separable mating halves and in which each half is connected in a fixed relationship to one of the pull cords. The separate mating elements are then releasably clipped or snapped into engagement with one another to join the cords. When a separating force is exerted between the elements, the elements snap apart, freeing the cords from one another and thus opening the loop. A variety of other releasable pull cord coupling devices have also been proposed, such as in the prior art or contemporaneous U.S. Pat. Nos. 5,473,797; 5,504,977 and 5,592,983 (each also being incorporated herein by reference).
Although such pull-tassel devices may generally be effective in releasably securing the cords together, many do not offer a particularly aesthetic solution to the problem, and others do not lend themselves well to known mass production techniques. Accordingly, despite such innovations in the art, there remains a need for a reliable safety tassel device having a pleasing appearance and, at the same time, a relatively simple structure that can be readily mass produced at a reasonable cost. In particular, there is a need for such a device that can effectively hold at least two cords for simultaneous manipulation and reliably release or separate the cords in response to a separating force exerted between them. In addition, the criteria of aesthetics and cost are particularly important in the competitive field of window coverings, in which purchasing decisions of designers, architects and users may turn on such factors, given solutions of comparable practical utility.
Moreover, there is an overriding and hitherto unmet need for such a safety pull-tassel system that can also solve the problem of a strangulation noose being formed when cord slack is pulled out from between the blinds when lowered, as well as the unmet need to solve the problem of safely equalizing the pull exerted by an array of plural pull cords.